CN1036145C - Sintered sol gel alumina abrasive filaments - Google Patents

Abstract

A sintered alumina based abrasive filament made up predominantly of fine alpha alumina crystals.

Description

Agglomerating sol-gel alumina base abrasive filaments and manufacture method thereof

The present invention relates to agglomerating collosol and gel αYang Hualv abrasive filaments, it is used for bonding abrasive product, and for example emery wheel, grinding segment, and coated article are for example among abrasive band, the abrasive disk.

Collosol and gel particularly adds the collosol and gel aluminous abrasive of crystal seed, since it is used several years ago, be widely used in applying with bonding grinding tool field among, confirmed that it has significant advantage than other high-quality abrasive materials.Usually such abrasive material all is owing to dry and sintering alumina hydrate gel are made.These gels also can contain the additive of certain different amounts, for example MgO, and ZrO ₂The dry material of crossing is crushed to required size range before sintering or after sintering irregular block polycrystalline grits into.Then these abrasive particles are attached to bonding or the abrasive product that applies in, for example emery wheel, grinding segment, the abrasive band becomes in the abrasive disk.

The United States Patent (USP) 4,314,827 of Lei Saishi (Leitheiser) etc. discloses the abrasive particle made from this quadrat method, and this method makes the agglomerating abrasive particle contain irregular " snowflake " shape α type Al of diameter on 5 to 10 micron number magnitudes ₂O ₃Crystal.Space between the spray of " snowflake " and adjacent " snowflake " is that the material by other phases captures, and for example grain aluminum oxide magnesium oxide point is brilliant.

The transferee who transfers Nuo Dun (Norton) company one this application that on December 18th, 1986 authorized, United States Patent (USP) 4,623,364 disclose a kind of method that is used to make the collosol and gel of alumina abrasive grain, and the goods except that applicator, film, filament, rod or undersized parts with better characteristic.In this patent, in the elementary thing of gel that seed crystal material adds in the gel or drying is preceding, change into αYang Hualv to impel hydrated aluminum oxide.This is to finish by the elementary thing of gel of band αYang Hualv medium or gel are carried out the hygrometric state vibro-grinding, or finishes by the seed particles of very thin Powdered or other shapes of direct adding.To add the crystal seed gel drying, and crush and fuse to make abrasive particle.So the abrasive particle of producing can be used for making such as abrasive disk and the such product of emery wheel.In addition, parts that be to make definite shape become rod, these materials are shaped before roasting or pass through the overflow mould moulding.Under the extruding situation, can be cut into after the rod of shaping and be broken into suitable length.

In case gel formation, it can be shaped by arbitrary method easily, and for example punching press, mold pressing or extruding are dried then carefully to produce the flawless product of desired shape.If expect abrasives, this gel also can push easily and diffuse into arbitrarily easily shape and be dried.After the drying, these solid products or material can be cut into or be processed into required shape, perhaps use suitable device, and for example hammer mill or ball mill are with its crushing or be broken into particle or abrasive particle.

This crystal seed collosol and gel abrasive material that adds has much solid α type Al than the non-crystal seed sol gel film of Lei Saishi (Leitheiser) type ₂O ₃The density of crystalline structure and Geng Gao.If add crystal seed and be not under the most appropriate mode, carry out or maturing temperature too high, or the time length is oversize, though might cause producing some thicker crystalline structure, this α type Al that adds crystal seed collosol and gel abrasive material ₂O ₃Crystal be superfine, and generally be on about 0.4 micron or the littler order of magnitude.

Other materials, for example Fe ₂O ₃Also can be used as and promote to change into α type Al ₂O ₃Crystal seed.Rule of thumb, such seed crystal material and Al ₂O ₃Should be isostructural, and should have similar (in 15%) lattice parameter and could play a role well.

For making the abrasive particle of desired size, just must be bigger grain breakage in the above-mentioned colloidal sol abrasive material, and its screening.Yet the very waste of this technology because the abrasive grain that it produces is in very large range.These abrasive materials can not used.This makes a considerable amount of abrasive particles have to abandon or recirculation production, or is used in the lower occasion of value.

Have now found that agglomerating collosol and gel micro crystal material has the characteristic that significantly improves, it does not need to carry out before use further grinding and processing, directly the fabulous shape of obtained performance.Because people custom thinks that the characteristic of collosol and gel microcrystalline alumina abrasive is from crystalline size and purity, especially want inclusion-free, this impurity is present in as in the bauxite, and causing when making the temperature of αYang Hualv forming glassy substances, the therefore this characteristic that has improved is wonderful especially.

In addition, because with direct formula technique production, thereby make the turnout much less of the material of non-direct requirement.In fact, nearly all material of production all is the requirement certain specification, and therefore, this complete processing is effective more significantly.

The present invention relates to the alpha alumina-based polycrystalline abrasive grit silk of agglomerating collosol and gel.If gel does not add crystal seed, the αYang Hualv crystal grain in the abrasive filaments can be greatly to 2 microns.But add best crystal seed, it can be less than 1 micron, and with best treatment process, it is not more than 0.4 micron.In general, can find that if crystal grain diminishes, then the abrasive material performance is significantly improved.It usually is superior that grain-size is approximately 0.05 to 1 micron the order of magnitude.Abrasive material can these gels are squeezed silk or get rid of silk, and these dryings, roasting be made to the step that is not higher than 1500 temperature by preparation hydrated aluminum oxide collosol and gel.Concerning best processing technology, it is included in initial colloidal sol or the gel and adds additive, the seed crystal material that promptly adds the ultramicro-crystal of significant quantity, it promotes that the hydrated aluminum oxide in the gel changes into very fine alpha alumina crystals rapidly when squeezing silk and dried collosol and gel roasting.Such seed crystal material example can be 3 aluminum oxide, gamma-alumina, chromic oxide, α ferric oxide, αYang Hualv, or the primary crystal product of these oxide compounds and other play a part the trickle chip of nuclear as αYang Hualv.

Crystallite forms from collosol and gel in process of growth, because can produce trickle uniform microlitic structure like this, when particularly having added crystal seed in collosol and gel.This process of growth is crucial, and it has formed the significant difference between product of the present invention and those products that mixture main or that be made up of αYang Hualv crystal grain is fully made by sintering.Unless use high temperature (it causes crystal growth), the latter's product always presents more weak sinter bonded power at adjacent intercrystalline, so the abrasive particle intensity of being made up of such crystal is less.On the contrary, growth forms from collosol and gel and agglomerating alpha alumina crystals then and there, and especially those can roasting protect trickle crystalline structure by adding the αYang Hualv that crystal seed technology produced under much lower sintering temperature.

Because impurity produces vitreous material when roasting, so preferably remove impurity basically in microlitic structure.So-called " glassiness " material meaning is meant does not have the amorphous substance that does not have long molecular chain of determining shape.This material has weakened all crystal grains structure significantly, and makes it become the relatively poor abrasive particle of effect.Therefore, containing less than 5% in the abrasive particle of the present invention, is this paste less than any of 2% weight preferably.

For ease of application and open, the present invention is at the term " silk " of this employing, refer to elongated ceramic body, each ceramic body generally is consistent along cross section on its length direction, its cross-sectional dimension is no more than about 1.5mm, preferably less than about 0.5mm, and its length preferably is maximum sized about 2 times of cross section greater than cross section overall dimension at least.Abrasive filaments of the present invention can crooked or distortion, so its length of course not along line measurement, but gets along its this scale of construction.

In general, abrasive filaments is preferably added the extruding of crystal seed alumina hydrate gel or is thrown away the successive filament by the best, with the filament drying that so obtains, and be cut into or be broken into the silk of desired length, then its roasting is obtained to being no more than 1500 ℃ temperature.

United States Patent (USP) 4,314 has been described the various methods that prepare hydrated aluminum oxide collosol and gel and roasting gel in 827,4,623,364 and 4,797,139.In described patent the disclosed hydrated aluminum oxide, also can comprise the additive of its weight item in the colloidal sol up to 10-15%, for example titanium dioxide, spinel, mullite, Manganse Dioxide, magnesium oxide, cerium dioxide, zirconium white, all powdered or primary crystal product form, or other compatible additives or its primary crystal product.These additives that provided do not produce glassy substances, and when filament formed, they did not produce deleterious effects to the integrity and the stability of gel under the temperature that αYang Hualv forms.These additives can improve the performance of gel, as fracture toughness property, hardness, fragility, fracture mechanical property or drying property.In most preferred embodiment, colloidal sol or gel change into the ultra tiny crystal seed material or the primary crystal product of αYang Hualv when comprising the promotion aqua oxidation aluminum sinter of significant quantity of disperse.The amount of this seed crystal material should not surpass the about 10% of hydrated aluminum oxide weight, and content surpasses at about 5% o'clock and just do not had what benefit under the normal circumstances.(preferably every gram has 60m if crystal seed is enough thin ²Or more), the amount of spendable crystal seed approximately is 0.5% to 10%, preferably 1% to 5%.Too much additive tends to influence the stability of collosol and gel, and makes it become the silk difficulty.In addition, because preformed alpha alumina particles needs much higher temperature ability sintering, so the intensity of key reduces greatly between the crystal that forms in sintering process.Certainly, high like this temperature causes crystal growth and other adverse consequences toward the contact meeting.

The example of solid-state crystallite seed crystal material is: βYang Hualv, α ferric oxide, αYang Hualv, gamma-alumina, chromic oxide and other can provide the trickle chip of the nuclear that plays a part αYang Hualv, and are best with αYang Hualv.Crystal seed also can the primary crystal product form add, as iron nitrate solution.In general, seed crystal material should be isostructural with αYang Hualv, and has similar lattice dimensions (in 15%), and (being approximately 1000 ℃-1100 ℃) shows its effect under the temperature that takes place to transform at αYang Hualv in the gel that drying is crossed.

Filament can have any one cross section easily, as circular, square, trilateral, star.In great majority were used, circular cross section was best.But some other application scenario, with other shape, for example square or trilateral may be better.

By the whole bag of tricks, for example push or throw away, from gel, can be made into wet abrasive filaments.Concerning diameter was the wet silk of 0.25mm to 1.5mm, it was the most useful squeezing a silk method.After drying and the roasting, it is 100 to 24 the used mesh size of abrasive particle that diameters of these wet silks are substantially equal to granularity respectively.Less than about 100 microns silk that needs roasting, it is the most effective getting rid of silk concerning diameter.According to the present invention, get rid of the silk that silk can be made into carefully the roasting of 0.1 micron (0.0001mm).Wet silk will shrink when roasting, and for example when 60% solids content, the diameter of its diameter when squeezing silk shrinks about 40%.

The gel of the most suitable crowded silk should have the solid of content about 30% to about 68%, and preferably about 45% to 64%.Best solids content is directly with the vary in diameter of extrude silk.Diameter is substantially equal to the filament in aperture of sieve screen apertures of abrasive particle (being approximately 0.28mm) that granularity is 50 crushing after roasting, it is preferably that solids content is approximately 60%, as mentioned above, usually attempt to obtain too high solids content, there is serious harm in the stability of gel by in gel, adding solid material.Usually the silk of extruding has only very low wet tenacity, and often can not keep the shape of silk, unless its diameter is during greater than about 2mm.

According to of the present invention get rid of the silk be that a certain amount of gel is placed on the disk, rotate then this disk will wet the silk throw away.The wet silk that throws away is almost dry at once in air.In addition, be drilled with in the centrifugal bowl of hole or seam around also gel can being placed on, this bowl, for example the speed rotation of changeing with per minute 5000 produces silk.In this process, these silks can be pulled to unthinkable " wet diameter ".Also available other known methods of getting rid of are produced wet silk.For getting rid of silk, the most useful solids content approximately is 20% to 45%, preferably about 35% to 40%.

If silk forms by getting rid of silk, need in forming the solution of gel, add an auxiliary that gets rid of of about non-vitreous of 1% to 5%, polyoxyethylene for example, with when becoming silk to the required visco-elasticity of colloidal sol increase.The best has gets rid of the auxiliary dosage of silk and becomes inverse change with solids content in the gel.Getting rid of an auxiliary has burnt in calcining or roasting process.Because the amount of required adding very little (generally not adding squeezing silk) is not so it can influence the performance of the silk of roasting one-tenth substantially.

By having the crowded silk mould of required crowded silk shape of cross section, gel can be squeezed into the gel filament of various desired shapes.If the cross section of gel filament is quite big or made by the gel that contains a large amount of water,, must or be preferably in drying below 100 ℃ 24 or 72 hours by being higher than before 100 ℃ being heated.When if the gel filament cross section is thin relatively or contain very high solids content, then there is no need to carry out drying treatment.

Certainly, abrasive filaments of the present invention can carry out drying treatment, and roasting to become basic successive silk be desirable.Reinforcing element for example a metal or a plastics structure of an essay that these can be used as in a kind of structure of an essay can make their toughness very excellent.

The initial successive silk that forms, required maximum sized length is used in the grinding that preferably is broken into or is cut to expection.In general, the successive silk is transformed into dispersion or changes the required any separation of its shape or forming process is preferably finished in gel phase or its drying stage.Because at this moment carry out, than what attempt after last roasting, to make according to the present invention much hard and also carry out during much firm silk laborsaving, cost is much lower.Therefore, when the successive silk produced from squeeze the silk mould, available all was known proper device concerning the personnel of present technique field arbitrarily, for example was contained near near the lip-deep metal filament revolution cutting unit crowded silk mould, and it is switched to desired length.In addition, the dry silk of crossing can be ruptured or be crushed a little the length range that the need that are divided into then are different.

Be shaped needed when gel filament has resembled, and be cut or crush, if necessary and after being dried, they are transformed into the silk of final form by controlled roasting process.Roasting should be enough to make the whole alumina compositions in the gel filament to change into crystal type αYang Hualv basically, but maturing temperature and time are all excessively unsuitable.Undesirable granularity and grain growth appear because overcook impels, thus cause the abrasive product produced in use effect reduce.In general, best adding crystal seed gel maturing temperature and the time is respectively 1200 ℃-1350 ℃, is proper between 1 hour to 5 minutes, though also can use other temperature and times.Concerning the silk that is coarser than 0.25mm, the silk of preferably drying being crossed is respectively about 400-600 ℃ at temperature and time, preroasting several hours to about 10 minutes, so that remove residual volatile matter and the moisture content that is bonded at wherein, this moisture content may produce slight crack in silk when roasting.It is general as United States Patent (USP) 4,314 that roasting does not add the crystal seed gel, temperature that disclosed such needs are higher in 827 and longer time.Particularly concerning from adding the silk that the crystal seed gel makes, to the bigger crystal grain of the degree very fast generation of roasting meeting, most of around they have absorbed or whole less crystal grain reduce the homogeneity of product on the microstructure rank thus.

Abrasive filaments particle of the present invention should have certain slenderness ratio, promptly along length on its principal dimension or the longer dimensional directions and the ratio of edge perpendicular to arbitrary maximum width on this principal dimension direction.This ratio is approximately 1: 1 at least.When cross section when being non-circular, for example Polygons uses the greatest measurement perpendicular to lengthwise degree direction to decide slenderness ratio.

Though also used longer silk in many application, its average slenderness ratio scope is preferably from about 2: 1 to about 8: 1.In the example of the present invention, the hardness of the most useful silk is at least 16GPa, and in major applications, it preferably is at least 18GPa.(Vickers pressure head, 500 gram load), its density preferably is at least 90% of theoretical density, and general the best is 95%.The αYang Hualv of pure density, the about 20-21GPa of hardness.Under certain conditions, at least in an embodiment of the present invention, abrasive filaments is distortion or curling in its lengthwise dimension direction, and the arc embayment that perhaps has to a certain degree is curved.

Can believe that in bonding abrasive applications, abrasive filaments crooked or distortion may be better than its corresponding linear silk, because more difficult extraction the out of the abrasive filaments that profile crooked or distortion makes such shaping gone from bonding.In addition, this abrasive filaments that curls or twist makes the emery wheel aerated density in the required scope of its easier acquisition.The diameter of abrasive filaments can be up to 1.5mm.Have been found that the bonded abrasive article with abrasive filaments production of the present invention is much better than the same goods that those contain crushing fusion and agglomerating abrasive material.The cross-sectional dimension of these abrasive particles (abrasive material size) approximates the diameter of abrasive filaments greatly.

Abrasive material filate particle of the present invention can be used for bonding abrasive product, for example emery wheel, grinding segment, and grinding stone, they all comprise binding agent and agglomerating collosol and gel abrasive filaments.The amount of binding agent and abrasive material by volume per-cent changes binding agent from 3% to 76%, abrasive material from 24% to 62%, pore from 0 to 73%.From these volume percent as can be seen, the bonding abrasive product that the filate abrasive material is produced is on softer grade, and the structure number that it has is more much higher than the structure number that big abrasive materials such as traditionally shaped size may have so far.Yet, traditional pore brings out for example hollow glass ball powder of medium, solid glass ball powder, hollow resin balls powder, solid resin balls powder, multicellular glass grain, alumina bubble or the like and analogue, can be attached in the emery wheel, and, with regard to the variation of hardness level and structure number, for these media provide bigger move place.

Abrasive product available heat thermosetting resin binding agent or vitrified bond are bonding.The thermosetting resin binding agent is based on that following material makes preferably, i.e. phenol formaldehyde resin, Resins, epoxy, polyurethane(s), polyester, lac, polyimide, phenoxy group, polybenzimidazole or their mixture.Binding agent comprises that also volume percent is 0 to 75% any one or a few weighting agent as known in the art or grinding additive.When caking agent was thermosetting resin, suitable weighting agent comprised sodium aluminum fluoride, iron sulphide, Calcium Fluoride (Fluorspan), zinc fluoride, ammonium chloride, chlorination alkene and dichloroethylene, politef, potassium fluoborate, vitriolate of tartar, zinc chloride, kyanite, mullite, nepheline syenite, molybdenumdisulphide, graphite, sodium-chlor and these various mixtures of material.

When in the ceramic bonding agent, adding weighting agent,, thereby limited the quantity of the useful weighting agent that adds to a certain extent because this caking agent requires the temperature of slaking higher relatively.But some weighting agent, kyanite for example, mullite, nepheline syenite, graphite and molybdenumdisulphide; The curing temperature that depends on specific pottery money caking agent during use.With grinding auxiliary dipping, for example fused sulfide perhaps floods the carrier of upward the grinding auxiliary being brought in the emery wheel pore, for example Resins, epoxy on the emery wheel of ceramic bonding.

During the abrasive product of the coating made from abrasive filaments of the present invention, abrasive filaments is attached on the flexible end liner, one end of silk is near adhesive linkage, and general this silk is protruding from flexible end liner, and usually applies one deck thereon with gluing coating it is bonded on the end liner securely.This end liner can be any known end liner that is used for coated abrasives, for example fabric of textiles or stitching, film or paper.According to the needs of using, be used to make the various known cloth of end liner or the finishing method and the material of paper industrial, also can similarly be used for preparing the end liner of coated abrasives silk of the present invention.Equally, also can use any known coating that is used for the standard production producer of coated abrasives production.

If the average slenderness ratio of abrasive filaments of the present invention can be, for example 1.5: 1 to 6: 1, in addition higher, then the roll coated technology of gluing coating available standards applies.If abrasive filaments has higher slenderness ratio, best with other equipment coatings, for example use spraying equipment, so just can not be abrasive filaments excessively to pressing down.Used gluing coating material can be the material of random known type used in coated abrasives industry.

Have been found that coated abrasives of the present invention has the longer life-span than the abrasive material that those contain the abrasive particle composition of crushing in the prior art basically.And the cutting speed in feet per minute of comparing them with coated abrasives of the prior art often fluctuates less, and the smooth finish that produces at workpiece surface in its useful life fluctuation is also little.

Be unexpectedly, also find with the coated abrasives that contains abrasive filaments of the present invention when carrying out the low pressure ground finish, effective especially.

The advantage of uniqueness of the present invention is to provide the coated abrasives of the abrasive filaments with various desirable length, and for special purpose, the distribution of sizes of abrasive filaments can be by desired accurate like that or variation, and this is can't obtain with the broken abrasive material of roll-in so far.

Further advantages of the invention are in containing the coated abrasives of abrasive filaments of the present invention, and abrasive filaments can be cut into all lengths or various slenderness ratio, but simulation silk mixture standard class CAMI.In addition, the abrasive material of coating can have the mixture of design, and this mixture has on grade, controllable diameter and superfine abrasive filaments.

Another advantage was when abrasive filaments used, and the waste that does not exist tradition to be produced at crushing abrasive particle type abrasive material is so production process is more economical more effective.

Abrasive filaments of the present invention and contain the bonded product and the coated article of this abrasive filaments as shown in following examples, generally is better than the abrasive product of prior art.Abrasive product of the present invention is suitable for the various types of metals of grinding, as various steel, resembles stainless steel, cast steel, hardened carbon tool steel; Various cast irons, malleableiron for example, malleable iron, spheroidal graphite cast iron, cold die casting iron and die casting iron, and various metal as chromium, titanium, aluminium.Because all abrasive material and bonded product or coated article all can contain abrasive filaments of the present invention, thus more effective than other analogous products during some metal of the grinding of abrasive material of the present invention and bonded product, more effective than other in some grinding application especially.

The explanation of most preferred embodiment.

Embodiment 1

In this embodiment, to mix through 5 minutes in the V-mixer of the bivalve of routine with 38.2 kilograms of grinding water liquid and 28.8 kilograms of distilled water of containing 1.37 kilograms of αYang Hualv crystal seeds than 196.4 kilograms of Pural NG type one water alumina powders that Kant Ah assists a meter GMBH (Condea chemieGMBH) to obtain, thereby form basic mortar uniformly.At this moment, in the blade of stirrer motion, with 44.6 distilled water dilutings and be added in this stirrer, remix is after about 5 minutes with 16 kilograms of nitric acid (70% concentration), colloidal sol just change into contain 61% solids component and include basically the gel of dispersive crystal seed equably.The crystal seed of this embodiment is with (the Diamonite Products Compamy of the diamond composition company of Ohio, Xi Fuwei, shreve, Ohio) the regulation grade of Huo Deing, contain aluminum oxide grinding working medium (each diameter 12mm of 88%, long 12mm) add on the grinding machine that distilled water is Sweco45 in model and grind, the particle in water (alumina seed) reaches 100M at least in water ²Till the particular table area of/g.

The purity of used Pural NG type powder is approximately 99.6%, and its accessory content is carbon, silicon-dioxide, magnesium oxide and ferric oxide.

The described crystal seed gel that adds by having the slick crowded silk mould of wall surface of the hole that many diameters are approximately 1.19mm, pushes the successive gel filament routinely.Then with these gel filaments under 75 ° of-80 ℃ of temperature and under dry 24-72 hour greater than 85% relative humidity.After the drying treatment, these silks are more crisp, can easily be broken into or be crushed to the silk of short length.In this embodiment, these are processed to the fiber yarn that its mean length is 2mm to 8mm.Then,, be heated to 800 ℃ with per minute less than 2 ℃ speed earlier, be heated to 1370 ℃ with the about 5 ℃ speed of per minute from 800 ℃ again, and, cool off then, thereby make it change into αYang Hualv 1370 ℃ of insulations 5 minutes down with these short silk roastings.After the cooling, the mean diameter of silk is approximately 0.58mm fully, and length is random, approximately is 1.5mm to 6mm, wherein is pure αYang Hualv basically.Its average crystal grain size is 0.3 micron, and Vickers' hardness approximately is 16GPa.Here, all grain-size is all measured by the intercepting method.

The diameter of above-mentioned these thread is that 30 standard abrasive particle is only a little bit smaller slightly than granularity.According to United States Patent (USP) 4,543, the 107 disclosed technology of owning together with Shandong firm (Rue), available conventional apparatus is made the thread abrasive particle of these fibers on the emery wheel of ceramic bonding.The contrast emery wheel is by the state of Massachusetts, and (Massachusetts) granularity of Chu Shouing is that 30 32A (treating with sulfurous acid) number fusion abrasive particle is made for Norton Company, Worces-ter in the Norton of Wo Ersaisite.These test emery wheels are made: diameter 178mm (7 inches), thick is 12.7mm (1/2 inch), and the centre hole of 31.75mm (one and one-quarter inch) is arranged.In each emery wheel, total percent by volume of abrasive material keeps 48% constant.The percent by volume of the vitrified bond of prescription A (seeing Table 1) keeps 7.21% constant.

Table 1

The fused oxide compound prescription SiO of binding agent A ₂47.61Al ₂O ₃16.65Fe ₂O ₃0.38TiO ₂0.35CaO 1.58MgO 0.10Na ₂O 9.63K ₂O 2.86Li ₂O 1.77B ₂O ₃19.03MnO ₂0.02P ₂O ₅0.22

100.00

Application No. 07/236,586, the applying date is on August 25th, 1988, transfers the same transferee of the present invention, does not make also at present that content is to use the example that adds a kind of vitrified bond described in the patent application of final examination result.A kind of in this binding agent is to be denoted as 3GF259A, is O.Hommel company (O.Hommel Company of Pittsburgh Pennsylvania) registration and sale by those moral Regensburgs of shore sunset Fa Niya.This fused binding agent is by 63% silicon oxide, 12% aluminum oxide, and 1.2% calcium oxide, 6.3% sodium oxide, 7.5% potassium oxide and 10% boron oxide are formed, and various compositions all are by weight percentage.Mixture and damp sand wheel are all made with traditional method.For cured glue, the damp sand wheel carries out roasting under 900 ℃.Roasting process is: rise to 900 ℃ with 25 ℃/hour speed from room temperature, and be incubated 8 hours down at 900 ℃, reduce to room temperature with free rate of cooling again.

When the vitrified bond composition with after abrasive material mixes, will test with emery wheel to be pressed into shape with needed 44.79% void content with punching block, emery wheel burnt to 900 ℃ in 43 hours then, and insulation 16 hours under this temperature, was cooled to room temperature again.Then, these baked emery wheels are repaired and surface working to the thickness of 6.35mm (1/4 inch), for the grind reliefs test is prepared.Fiber yarn abrasive grinding wheel label of the present invention is SN119, is 32A30 and make correlated traditional fused abrasive grinding wheel label.The material that is ground is D ₃Tool steel is hardened to R _c60, the length of the groove of grinding is 40.64cm (16.01 inches).Test is carried out with Brown type and Sharpe type plain grinding, and speed of grinding wheel is decided to be 30.48smpm (6000sfpm), and table speed is decided to be 0.254mps (50fpm).During test, the downward amount of feed of each round trip is respectively 0.025mm, 0.051mm, and three kinds of 0.076mm (1,2 and 3 mil), total stock removal is 1.524mm (60 mil).When every kind of amount of feed grinding, all to the abrasion loss of emery wheel, the amount of metal and the power demand of cutting are measured.By table 2 and later on used term " G-ratio ", refer to when given ground finish, its numerical value is for every kind of given grinding rotating speed, the volume that the measured metal volume that grinds away is fallen divided by measured abrasion of grinding wheel.Shang Yuegao, then the emery wheel quality is good more.Test-results is as shown in table 2.

Table 2

Dry grinding D ₃Go up the result of groove on the steel

Abrasive material (type) the emery wheel model amount of feed (millimeter) G-compares specific power

S/W joule/millimeter ³

Fusion 32,A30 0.025 4.0 19.35

(bulk) 0.05 4.25 24.62

0.076 stall stall

Sintered type 0.025 30.28 13.95

(squeezing the silk type) SN119 0.051 21.31 13.40

0.076 48.16 24.41

Wheel face speed dry grinding D with 152.4 meters of per minutes (6000 inches) ₃During steel, the life-span of the emery wheel that abrasive particle according to the present invention is made is best, and it is 5 to 10 times of life-span with traditional emery wheel that the molten mass shape abrasive particle of identical cross-section diameter makes, and grinding unit volume steel institute wasted work rate is little.

When the high-speed grinding metal, the advantage of the made emery wheel with long filament shape abrasive particle is obvious especially according to the present invention.To given grinding grade, the emery wheel that contains the filate abrasive particle is more freely almost as the lower power consumption level grinding shown in the table 2, and the generation less calories, also can not burn out the clean degree of table of workpiece surface.For making cutting tool, avoid producing metal man-hour and damaging adding, it is essential that low-heat does not burn out finished surface.

Embodiment 2

In this embodiment, the ceramic bonding grinding segment is to make with the same abrasive particle described in the embodiment 1.These grinding segments are made and are suitable for being installed on bridge Te Langde (chorland) chuck of 30.48cm (12 inches) diameter.Each grinding segment is 12.7cm (5 an inches) height, and the chord length that cross section equals on 30.48cm (12 inches) circle is the cross section that 19.05cm (7.5 inches) locates.This grinding segment is to make to make the same method of emery wheel among the embodiment 1.Traditional grinding segment and abrasive material grinding segment of the present invention that present used best fusion abrasive material is made carry out the grinding comparative experiments, be with and Blang looks into moral (Blanchard) vertical shaft plain grinding, on the square steel plate of 30.48cm (12 inches) that No. 1018 steel are made, carry out.Carry out the wet type grinding with the molten water oil of 1: 40 ratio and the cooling fluid of water.

The speed of three kinds of downward feedings of test: 0.406mm/ branch (0.016 inch per minute), 0.559mm/ branch (0.022 inch) and 0.711mm/ branch (0.028 inch per minute).In each case, the total amount of the amount of feed is 2.54mm (100 mil) downwards, divides four feedings.Grinding segment abrasion loss, the amount of metal of grinding and measurement of power are all carried out in each feeding.Its result is as shown in table 3.

Table 3

The plain grinding result of grinding segment on 1018 steel

Abrasive material grinding segment speed of feed G-specific power

(model) (mm/ branch) be (KW) (S/W)

Fusion 0.406 7.44 8.4

(bulk) 32,A30 0.559 5.75 12.0

0.711 4.48 12.0

Sintered type 0.406 34.32 8.8

(squeezing the silk type) SN119S 0.559 12.64 9.2

0.711 12.64 9.6

As can finding out from result shown in the table 3, the grinding segment that filate abrasive material of the present invention is made, G-than aspect, its serviceability is better than 300% to 500% of the fusion abrasive material grinding segment that uses at present, and watt consumption reduces significantly when high feeding.

Embodiment 3

In this embodiment, produced the less filate abrasive material of a collection of diameter, they be with 3.2 kilograms of Pural NG type one water aluminum oxide with contain 22 grams and embodiment 1 in the water liquid of the same grinding that contains the αYang Hualv crystal seed mix for 1.39 kilograms.Mixed 5 minutes, and added 70% nitric acid, 200 grams, mixed continuously again 5 minutes, contain the equally distributed therein gel of 59% solid crystal seed thereby form by the 750ml distilled water diluting.Then, be the slick crowded silk mould of porous surface of 0.6mm with the aperture, the gel that in a conventional manner these is added crystal seed squeezes silk.After the silk drying that is extruded into, be cut into mean length and be the short silk of 3mm, then roasting to 1320 ℃ and be incubated 5 minutes.After the roasting, it is 50 abrasive material that the cross-sectional dimension of single silk is equivalent to standard particle size.Under 1320 ℃ maturing temperature roasting 5 minutes than among the embodiment 1 short slightly a bit.But in embodiment 1, its bending or the distortion.Except that grinding wheel diameter is 127mm (5 inches), abrasive filaments is made the test emery wheel by embodiment 1 described technology.Making correlated emery wheel is to be made by the crystal seed sol-gel alumina abrasive material that adds identical with the filate abrasive components, but this abrasive material is exsiccant sand cake to be become the block abrasive particle similar to the fused alumina abrasive particle make.The emery wheel label that contains filate abrasive material of the present invention is X31-1, and block collosol and gel abrasive particle grinding wheel label is SN5.Carry out grinding by the groove to the D3 steel that hardens described in the embodiment 1, these emery wheels are experimentized, experimental result is shown among the table 4.

Table 4

To D ₃The result that the groove of steel is dry grinded

Abrasive material (type) emery wheel feeding G-compares specific power

(mm) (S/W) joule/millimeter ³

Collosol and gel 0.013 24.3 62.8

(bulk) SNS 0.025 35.8 42.3

0.051 28.8 28.9

Collosol and gel 0.013 26.27 49.7

(squeezing the silk type) X31-1 0.025 48.58 35.2

0.051 73.78 23.75

These results clearly show, and filate sol-gel alumina abrasive material is more superior than block abrasive particle sol-gel alumina abrasive material.When high-feed, abrasive particle of the present invention has the G ratio up to 255%, and consumes 18% power less.

Embodiment 4

In this embodiment, made the phenolic resin bonded light emery wheel of hot pressing of 4 cover standards with traditional method, diameter is 15.24cm (6 inches), and thick 1.59cm (0.625 inch) also has the centre hole of 1.59cm (0.625 inch).The first cover emery wheel contains United States Patent (USP) 3,891, the block abrasive material (AZ) of 408 described aluminum oxide one zirconium white congruent meltings; The second cover emery wheel contains United States Patent (USP)-4,623, the granularity described in 364 be 16 (USS screen cloth series) add the block abrasive material (SGB) of crystal seed sol-gel method; The 3rd cover emery wheel contain described in the foregoing description 1 but diameter is the filate of 1.5mm (0.074 inch) adds crystal seed sol-gel alumina abrasive material (SGF).All emery wheels are except that the abrasive type difference, and other are all basic identical.They all are that quite high hardness level is arranged, and its composition constitutes volume percent and is: abrasive material 48%, binding agent 48%, pore 4%.All emery wheels all carry out ground finish with identical condition to rail in grinding process.As basis of reference, its result is as shown in table 5 with the emery wheel of aluminium oxide-zirconium oxide (AZ) abrasive material that contains known congruent melting.

Table 5

Rail grinding test (relative result %) abrasive material changes power constant abrasion of grinding wheel rate metallic substance grinding rate power G-ratio

(KW)AZ 100.0 100.0 100.0 100.0SGB 1.7KW 239.9 116.8 106.7 48.6SGF 140.2 141.6 107.8 101.0AZ 100.0 100.0 100.0 100.0SGB 2.2KW 286.4 117.7 101.2 41.1SGF 149.1 137.2 103.8 92.0AZ 100.0 100.0 100.0 100.0SGB 2.3KW 152.7 99.0 101.4 64.8SGF 140.0 128.2 99.6 91.5AZ 100.0 100.0 100.0 100.0SGB 2.5KW 248.3 107.5 103.1 43.3SGF 117.5 120.9 103.5 102.9

By the G ratio in the table, it is the volumetric ratio of the material of per unit abrasion of grinding wheel amount institute grinding, can find out that it is much superior that the whole mass ratio bulk of now used AZ type abrasive material adds crystal seed collosol and gel abrasive filaments, and wherein said filate adds a crystal seed collosol and gel abrasive material roughly equiv in AZ type abrasive material.Yet during the grinding rail, key is that rail must carry out the grinding repairing in the short as far as possible time, and therefore, the speed of grinding metal has just become to estimate the deciding factor of the emery wheel quality of grinding rail.Contain that metal removal rates that filate adds crystal seed collosol and gel abrasive grinding wheel is better than AZ type abrasive grinding wheel greatly and bulk adds crystal seed collosol and gel abrasive grinding wheel.Under several grinding operating modes, the weight metal that the filate abrasive grinding wheel grinds off is great more about 42%, 37%, 28% and 21% than the difference of AZ molding sand wheel, adds good about 25,20,29 and 13 percentage points respectively of crystal seed collosol and gel abrasive grinding wheels than bulk.Filate adds crystal seed collosol and gel abrasive material also not to be understood fully fully than the superior reason of corresponding block abrasive material, but can conclude that difference exists really.

Embodiment 5

According to known method, people have made a series of business-like phenolic resin bonded abrasive cut-off wheels, and these emery wheels are of a size of 50.8 * 0.33 * 2.54cm (20 * 0.130 * 1 inch), and both sides reinforce with the emery cloth dish.The diameter of these dishes is approximately 1/2 of grinding wheel diameter, and the diameter of for example reinforcing overcoat is about 25.4cm (10 inches).An emery wheel of/3rd is 24 (based on USS screen cloth series) by granularity, and the block aluminum oxide of the fused crushing that Norton (NortonCompany) sells is made.The label of this aluminum oxide is known as ALUNDUM57A, and ALUNDUM is the trade mark of Norton (NortonCompany) registration.United States Patent (USP) 4,623, the 364 described granularities that other 1/3rd emery wheel contains above-mentioned Kao Chuige (cottrinher.et al) are 24 to have bulk to add crystal seed collosol and gel abrasive material (SGB).Last 1/3rd emery wheel contains filate of the present invention and adds crystal seed sol-gel alumina abrasive material (SGF), its cross-sectional area be substantially equal to granularity be 24 each to 57A type abrasive material that equates and the block diameter that adds crystal seed collosol and gel abrasive material, for example be approximately 0.74mm.By volume is calculated, and all emery wheels all contain 48% abrasive particle, 46% binding agent and 6% pore.

C1018 steel that 3.81cm (1.5 inches) is thick and No. 304 thick stainless steels of 3.81cm (1.5 inches) carry out dried cutting experiment with emery wheel.Test is carried out on M150 type stone cutting machine.Emery wheel turns round with the surface velocity of 3657.6 meters of per minutes (12000 feet), and carries out 30 cuttings.The time that each emery wheel cuts on C1018 steel and No. 304 stainless steels is 2.5 seconds and 4 seconds.Cutting C1018 steel and No. 304 stainless comparative experiments results are shown in respectively among following table 6 and the table 7.

Table 6

Material cutting-C1018 steel

Relative G-is than emery wheel (type) wear rate loss rate No. (second) (cm for abrasive material cutting time metallic substance emery wheel mill G-specific power ³/ minute) (cm ³/ minute) (KW) %1 57A 2.5 89.65 13.44 6.67 14.26 1002 57A 2.5 89.00 13.27 6.67 13.97 1003 57A 4.0 56.54 12.29 5.58 9.27 1004 SGB 2.5 89.65 8.36 10.79 12.67 193.45 SGB 2.5 90.30 8.36 10.79 13.20 193.46 SGB 4.0 56.05 6.55 8.65 8.79 155.07 SGF 2.5 90.30 5.24 17.24 11.90 258.58 SGF 2.5 88.34 4.10 21.54 11.95 322.99 SGF 4.0 55.23 2.62 21.54 8.04 386.3

Contain filate and add crystal seed sol-gel alumina abrasive material (SGF) emery wheel, when cutting C1018 steel, its overall performance and G-contain the emery wheel of the block abrasive material (SGB) corresponding with SGF type abrasive material and contain the emery wheel of fused alumina abrasive material 57A very superior frequently.When be 2.5 seconds clipping time, the G-ratio of the 57A molding sand wheel that the G-of SGF emery wheel is corresponding frequently exceeded 158.5 percentage points.When be 4 seconds clipping time, then exceed 370.3 percentage points.Although SGF surpasses the advantage of SGB and do not resemble so greatly above 57A, but still is very big, promptly when be 2.5 seconds clipping time, exceed 93.4 percentage points; When be 4 seconds clipping time, exceed 55 percentage points.People should also be noted that except that much higher grinding quality (G-than), and the power that the SGF emery wheel consumes is also done all than 57A or SGB abrasive sand with kilowatt (KW) metering and lacked significantly.The summation of the power of the SGF emery wheel consumption of all three tests is 31.89, and three SGB emery wheels are that 34.66, three 57A emery wheels are 37.55.So the SGF emery wheel saves 15.1% than the emery wheel that contains the 57A abrasive material, than the emery wheel save energy 7.9% that contains the SGB abrasive material.

Table 7

Cutting material-No. 304 stainless steel

Relative G-is than emery wheel (type) wear rate loss rate No. (second) (cm for abrasive material cutting time metallic substance emery wheel mill G-specific power ³/ minute) (cm ³/ minute) (KW) %10 57A 2.5 90.30 17.70 5.11 12.96 10011 57A 2.5 88.34 15.07 5.85 12.06 10012 57A 4.0 56.54 7.86 7.22 8.94 10013 57A 4.0 56.05 6.39 8.66 9.12 10014 SGB 2.5 92.44 8.52 10.79 12.43 211.215 SGB 2.5 90.30 8.36 10.85 12.34 185.516 SGB 4.0 57.36 3.27 17.24 9.09 238.917 SGB 4.0 56.54 3.27 17.24 8.61 200.518 SGF 2.5 87.52 6.06 14.43 11.81 282.419 SGF 2.5 86.86 6.06 14.43 12.48 246.720 SGF 4.0 55.56 2.62 21.54 8.82 298.321 SGF 4.0 54.25 2.46 21.54 8.43 248.7

The same during with cutting C1018 steel, the SGF emery wheel is better than the 57A fusion crushing alumina abrasive emery wheel of use now greatly; Also more superior significantly than SGB abrasive grinding wheel.When be 2.5 seconds each clipping time, the G-of SGF emery wheel compared the 57A emery wheel and exceeds 182.4 and 146.7 percentage points.When be 4 seconds each clipping time, same difference was 198.3 and 148.7 percentage points.Compare with the emery wheel that contains the SGB abrasive material, when the SGF emery wheel is 2.5 seconds in each clipping time, have 71.2 and 61.2 percentage points advantage; When be 4 seconds each clipping time, has 59.4 and 48.2 percentage points advantage.With regard to watt consumption, the power major part of SGF emery wheel consumption all will be saved than 57A and SGB emery wheel, but the saving amount is relatively littler.

Embodiment 6

Can make the commercial phenolic resin bonded abrasive cut-off wheel of quadruplet with traditional method, it is of a size of 50.8 * 0.22 * 2.5cm (20 * 0.130 * 1 inch), and both sides reinforce with the emery cloth dish of grinding wheel diameter 1/2.The per-cent of emery wheel composition volume is abrasive material 50%, binding agent 32% pore 18%.The first cover emery wheel is ALUNDUM53 (53A) type according to USS screen cloth series with the trade mark, and granularity is that 50 the fusion block alumina abrasive of crushing is made.ALUNDUM is Norton (NortonCompany, of Worcester, Massachusetts) Zhu Ce the trade mark of state of Massachusetts Wo Ersaisite.United States Patent (USP) 4,623, the 364 described block agglomerating that the second cover emery wheel contains Kao Chuige (cottringer et.al) add crystal seed collosol and gel abrasive material (SGB), and its granularity also is 50.The 3rd cover and quadruplet emery wheel contain respectively described in the foregoing description 1 but its cross section is that to be substantially equal to granularity in the 53A emery wheel be that each filate sintering to the diameter of equal abrasive material of 50 adds crystal seed collosol and gel abrasive material and bulk adds crystal seed collosol and gel abrasive material.All add the crystal grain that crystal seed collosol and gel abrasive material all has the superfine size, the abrasive particle diameter of back two cover emery wheels is approximately 0.28mm (0.011 inch), but it is 9 average slenderness ratio that emery wheel 26 and 27 has numerical value, and emery wheel 28 and 29 has numerical value is 9 average slenderness ratio, and the average slenderness ratio of emery wheel 28 and 29 is 6.These emery wheels are respectively SGF (a) and SGF (b) in table 8.

With model is that Compball 406 type swing type cutting machine cutting diameters are No. 4340 rod irons of 10.16cm (4 inches).Cutting is that amplitude of fluctuation is that 4.12cm (1.62 inches) carries out with per minute swing 57 times.Simultaneously cutting area is carried out water-cooled, be 1 minute and 2 minutes clipping time.The abrasive cut-off wheel surface velocity is 3008.37 meters of per minutes (9870 feet).The result is as shown in table 8.

Table 8

-No. 4340 stainless steels of material cutting

The emery wheel abrasive material is relatively on average average relatively clipping time

No. (type) (second) the G-specific power

22 53A 60 100 100

24 SGB 60 113 97

60

26 SGF(a) 60 319 101

60

28 SGF(b) 60 335 102

60

23 53A 120 100 100

25 SGB 120 99 84

27 SGF(a) 120 350 103

120

29 SGF(b) 120 401 102

120

G-compare=records the material mill and contributes damage amount and the volume ratio that records the abrasion of grinding wheel amount.

When be 60 seconds each clipping time, two kinds contained the filate agglomerating and add crystal seed collosol and gel SGF (a) and SGF (b) emery wheel and crush than widely used fusion that to add crystal seed collosol and gel abrasive material SG grinding wheel performance superior for 53A alumina abrasive emery wheel and block sintering.Contain the G-ratio of the emery wheel of SGB abrasive material, higher 13 percentage points than 53A emery wheel, but SGF (a) and SGF (b) emery wheel are higher 219 and 235 percentage points respectively than the 53A emery wheel of standard.When cutting diameter is that 53A emery wheel and SGB abrasive grinding wheel performance are roughly the same when time of 10.16 centimetres rod iron slowing down to 120 seconds.But two kinds to contain the performance that the filate agglomerating adds crystal seed collosol and gel abrasive grinding wheel SGF (a) and SGF (b) (G-than) higher 3.5 times and 4 times respectively than 53A emery wheel and SGB emery wheel.The watt consumption of two kinds of SGF emery wheels of the present invention and 53A does not have difference basically.Concerning some contains the emery wheel of SGB and 53A, though the low 25-30% of watt consumption, but from the average relatively G ratio that the filate sintering adds crystal seed collosol and gel abrasive grinding wheel be higher than they 209 to 301 percentage points, it is dark right eclipsed that its meaning also seems.

Thread another purposes that adds crystal seed gel abrasive material is to be used in the abrasive product of coating.It demonstrates the longer beyond thought ability of SG abrasive material of the time ratio roll-in that keeps high speed cutting in this product.

Embodiment 7

This embodiment compares grinding and the smooth finish that filate adds the SG abrasive particle that grinding that crystal seed gel (SG) alumina abrasive grain carries out and smooth finish and traditional roll-in obtain.It is 50 abrasive particle 0.0353cm that filate abrasive particle mean diameter 0.033cm, (0.013 inch) are substantially equal to granularity, (0.0139 inch), and its long fineness ratio can chosen wantonly in the scope from about 2: 1 to 8: 1.Yet as described below, used batch screening causes some very long silk and extremely disproportionate a large amount of imperceptible grain to produce.The composition of abrasive filaments and granularity are that 50 SG2011 crushing type preparation is identical.

Table 9

Classification results particle (type) row No. grain size category LPD roll-in 08D168.3 50+3.2+1.9 180.7 abrasive filaments 08D168.7 50-2.5+30.9 209.7 of roll-in abrasive material and abrasive filaments

Can find out that from last table two kinds of different abrasive particle changed in stages are very remarkable each other.Reading "+3.2+1.9 " the meaning is, when experimentizing with CAMI sizing screen system, roll-in abrasive particle sample is thick, and to cross rank high by 3.2%, carefully crosses grade that other is high by 1.9%.To granularity is 50 SG abrasive particle, and this tolerance is within the range of permission.To the sample of abrasive filaments, its reading is " 2.5+30.9 ", and representing this sample, thick to cross level else low by 2.5%, carefully crosses level other is high by 30.9%.This is an extremely disproportionate numerical value, and it all is same shape that the high scale of thin end causes abrasive filaments " abrasive particle ".Numerical value is low more, and the ratio of approximate diameter is big more, and this diameter is that 50 the size with reference to screen cloth is little than granularity.

The abrasive lapping dish for preparing with traditional method.Its coat weight approximately is: bonding coat 15#/RM, last gel coating 23#/RM abrasive filaments 65 grams, roll-in abrasive particle 52 grams.

After the bending of routine, made abrasive filaments abrasive disk is at first identified in low pressure passivation experiment.Table 10 has been listed the comparative result that carries out grinding and smooth finish:

Table 10

On the flat steel plate of 7.62cm (3 inches) the filate abrasive material with

The roll-in abrasive material carries out the comparison of grinding and smooth finish

Grinding smooth finish time granularity is that 50 SG granularity is that 50 filate granularity is that 50 SG granularity is that 50 filate contrasts abrasive material abrasive material contrast abrasive material abrasive material No. grinding accumulative total grinding accumulative total at interval and grinds the surface smoothness surface smoothness

The interval amount of cutting is the amount of cutting at interval

GMS GMS GMS GMS Ra Rtm Pc Ra Rtm Pc1 29 29 20 20 164 1005?227 125 995 2112 26 55 17 37 105 736 265 103 855 2334 18 94 15 68 80 625 163 109 757 1566 12 119 10 92 48 414 115 53 386 828 8 136 9 112 37 331 103 33 268 7310 4 146 8 128 34 282 96 28 222 9112 - - 7 143 - - - 28 193 9214 - - 5 154 - - - 40 297 81

The bisector error of Ra=micron meter;

The crest of Rtm=micron meter and trough average height;

Pc=crest number.

The smooth finish quality of metal works is weighed with Ra and Rt value usually.This Ra and Rt value are that the sweep trace by the point on the workpiece surface that polished (as center, right hand edge, left hand edge) records.The meaning of these statistical parameters is known to those skilled in the art, and what publish by Industrial Metal Products Co., Ltd (Industral Metal Products Incorporate Lmp (IMPCO)), clearly descended definition in (surface structure and component geometrical shape are drawn opinion) by name book, and it has been done complete disclosing, enroll only for referencial use here.In general, Ra is the observed value of surface average roughness.Because the different surface of many profiles has similar Ra value, so this numerical value uses other parameters of recording from similar face as a supplement.In the medal polish technology, the Rt value usually is used for replenishing the observed value of Ra.The Rt value is to be recorded by the workpiece surface after the polished finish residual cut or width of nick.Pc is often referred to the cut frequency number.

From above-mentioned value as can be seen, it is more superior than traditional roll-in abrasive lapping dish when grinding to contain the abrasive disk of abrasive filaments.Originally, in initial several timed intervals, the abrasive filaments abrasive disk carries out long continuous grinding with lasting speed then with lower speed grinding.The surface smoothness that is produced by abrasive filaments seems to be substantially equal to the surface smoothness that the roll-in abrasive material produces.Yet, must point out again that the screening of the batch of filate abrasive grain causes the generation of aforesaid extremely disproportionate a large amount of superfine abrasive particle and very long abrasive filaments, thereby just may produce different smooth finish with more controlled screening.

For the roll-in abrasive particle grinding of the granularity 50 of abrasive filaments and 36 and the smooth finish of generation are compared, done further experiment.The test specimen surface is 2.54 centimetres (1 inches), the results are shown in the table 11.

Table 11

Abrasive filaments and roll-in abrasive particle on the steel surface of 2.54cm (1 inch)

Carry out the comparison of grinding and smooth finish

Grinding smooth finish

Granularity is that granularity is that granularity is that granularity is that granularity is that granularity is

952 of 50 SG 50 ^#952 of the SG 50 of 36 SG 50 ^#36 SG

Contrast abrasive particle abrasive particle ^*The contrast abrasive particle ^*Contrast abrasive particle abrasive particle ^*The contrast abrasive particle ^*

Accumulative total stock removal surface smoothness surface smoothness surface smoothness

(gram) Ra Rtm Pc Ra Rtm Pc Ra Rtm Pc1 41 31 44 152 1,053 214 207 1,455 149 226 1,181 1,635 215 189 256 154 852 195 196 1,279 173 205 1,079 22,410 438 419 526 119 839 233 158 1,019 179 135 840 11,715 627 640 779 136 1,018 243 136 714 159 128 711 28,420 779 859 1,001 63 599 353 124 730 196 129 820 14,525 880 1,060 1,181 41 420 320 92 581 230 75 526 17,930 926 1,228 1,334 42 254 100 80 423 152 73 534 18135-1350 1437---87 477 139 54 394 16840-1444 1506---48 431 200 70 359 18144-1496 1541---73 489 96 80 503 11548-1532----65 347 90---

*=abrasive filaments:

Ra=micron meter bisector error;

Rtm=micron meter crest is to the trough average height;

Pc=crest number.

By The above results as can be seen: when grinding, granularity is that 50 abrasive filaments not only is 50 roll-in abrasive material superior performance than granularity, and stock removal equals the stock removal that granularity is 36 contrast abrasive particle.Have, when initial, abrasive filaments is with a certain speed grinding lower slightly than roll-in abrasive particle again, but after, it is with the longer time of sustained speed grinding.The lip-deep test of steel at 2.54cm (1 inch) shows, it is the smooth finish that 36 contrast abrasive particle produces that the smooth finish that the filate abrasive particle produces is comparable to granularity.

Embodiment 8

This embodiment has illustrated with opposite with sintering the structure producing method with cohesive force into behind the crowded silk of αYang Hualv abrasive particle in suitable medium, produces the effect and the effect of the mode of filate αYang Hualv then and there.

This product according to the present invention is to produce like this: mix boehmite, boehmite with the αYang Hualv of the superfine of 10% weight mixed in V-mixer two minutes with water, with weight percent is 18% salpeter solution to be arranged, weight according to boehmite is the nitric acid that the basis adds 7.21% weight, continue again to mix 5 minutes, thereby form boehmite gel.

For carrying out comparison corresponding to above-mentioned example, prepare a series of products, except be to add more αYang Hualv (as above-mentioned seed crystal material the sort of) in order to make whole mixture contain much higher alumina weight per-cent.Keeping boehmite is in order to provide the extruding of mixture.Its prescription is provided by following table 12.

Table 12 lot number composition changes relatively type B* αYang Hualv 30% 70% type D αYang Hualv 90%/gel 10% type E aluminum oxide 60%/gel 40% type F αYang Hualv 60%/gel 40% example 1 αYang Hualv relatively relatively relatively of percent solids % comparison A αYang Hualv 30% 70%, (crystal seed) 1% 62% example 2 αYang Hualvs, (crystal seed) 1% 58% example 3 αYang Hualvs, (crystal seed) 1% 59%

*: with ultrasonic wave mixed pulp is mixed in addition.

Then these materials are squeezed into silk, carry out drying and sintering more under the following conditions.The batch of material of the usefulness as a comparison that sintered alumina content is high than sintering by adding the higher temperature of batch of material needs that the crystal seed sol-gel process produces.With Instron type trier.With the head lateral velocity of 0.2cm/min,, sample filaments is made a strength test according to simple bikini treatment process.Silk is bearing on 1cm ('s being 0.9cm under the situation of comparison C, D, E) a pair of seamed edge, exerts pressure downwards in this centre of 2 by the edge of a knife.This pressure increases gradually, ruptures up to silk.This pressure is exactly the breaking tenacity shown in the table 13 divided by the cross-sectional area of silk.

Table 13 unit: kg/cm ²

The diameter breaking tenacity of lot number maturing temperature roasting time silk

(mm) mean value higher limit

1500 ℃ of comparison As 30 minutes 0.32 6,831 7,465

Relatively 1550 ℃ of type B 30 minutes 0.3175 6,162 6,268

Relatively 1450 ℃ of type C 60 minutes 1.00 5,424 6,646

Compare 1300 ℃ of 6 fens .88 of type D 3,430 4,036

Compare 1350 ℃ of 6 fens .87 of type E 2,378 2,436

1 1370 ℃ of examples 4 minutes 0.054 11,197 13,239

2 1350 ℃ of examples 30 minutes 0.043 14,366 15,986

1350 ℃ 5 minutes 0.046 14,154 17,112

1325 ℃ 30 minutes 0.046 14,296 16,549

1350 ℃ 30 minutes 0.053 10,281 14,859

3 1350 ℃ of examples 30 minutes 0.020 16,000 18,169

Because before squeezing silk back and roasting, the silk batch of material of making comparisons is difficult to be extruded into the complete silk of thinner size, so their size is much thick.Can find that higher αYang Hualv content ratio makes the more remarkable aggravation of this problem.

More as can be known, the silk of making comparisons has significantly low breaking tenacity by above-mentioned numeric ratio.Can believe that this has reflected because the result of sintering processes makes the sinter bonded power that produces between the alpha alumina crystals weak more.Therefore, when measuring, has 8000kg/cm at least on the preferred silk of the present invention cross section by embodiment 8 described experiments ², be preferably 10000kg/cm at least ²Breaking tenacity.This product with the low breaking tenacity that is obtained by the preformed αYang Hualv of sintering forms sharp contrast.

Embodiment 9

This embodiment has illustrated the production that adds crystal seed collosol and gel silk of the present invention.

The 200ml distilled water that will contain 20 gram polyoxyethylenes mixes with the water that 28ml contains αYang Hualv, and this water has carried out the Sweco formula with αYang Hualv and ground, till water contains 5% αYang Hualv solid.This mixture is carried out mixing lenitively in 16 hours, add 200 grams, one water aluminum oxide then, (condea NG) was Hobart type stirrer for mixing 5 minutes.The nitric acid that adds 8 milliliter 20% again, whole mixture further mixed 5 minutes again.

Final mixture is a kind of sticking elastogel, and placing it in diameter is in the bowl of 15.24cm (6 inches).A Plexiglas's plate is fixed on its top.This bowl is contained on the vertical type motor axle, and is sealed in the square casing of the 182.88cm (6 feet) that is with the transversal ventilation device.Bowl is with the speed rotation that per minute 2500 to 3500 changes, force gel outside and upwards gush, it makes Plexiglas's lid displacement and opens a seam.Therefore gel outwards throws away thus and increases into silk.Because these diameter is very little, so done soon.Fiber shape silk is collected on the screen cloth of relief outlet, then with rise 15 ℃ speed roasting of per minute, reach 1350 ℃ after, be incubated 15 minutes.The fiber shape silk of collecting is highly purified, and form by superfine αYang Hualv crystal grain more than 99%.

Embodiment 10

This embodiment has illustrated except that by the production of extruding the different filate material that adds other shapes the right cylindrical silk that the crystal seed sol-gel alumina makes of cross section.As the application described the consistent used term of filamentary material part, the cross-sectional dimension of silk was described with " granularity ".

Its product is shown in down in the tabulation 14.

Table 14

Granularity 110 24 24 28 24 50

The square tubulose of shape (cross section) (macropore) tubulose (aperture) trilateral is circular

Maturing temperature ℃ 1,270 1,270 1,270 1,270 1,250 1250

Roasting time (branch) 5555 18 18

Hardness (GPa) 19.6 20.9 20.3 18.7 18.9 20.1

Diameter (mm) 0.14 0.89 0.89 0.71 0.91 0.33

L/D 5.8

Density (g ^*/ cc) 3.84 3.89 3.90 3.91 3.88 3.86

Grain size 0.14 0.19 0.18 0.17 0.16 0.18

(micron)

*: measure with the helium specific gravity hydrometer

When being used as abrasive material, above-mentioned all abrasive particles all demonstrate excellent performance.

Embodiment 11

This embodiment illustrates the influence of grain size to the grinding performance of abrasive material of the present invention.

Except that a collection of (be its bigger grain-size of G can by add crystal seed technology remove the most easily obtain), the abrasive particle of other lot numbers is all by adding the production of crystal seed sol gel process.

The abrasive particle characteristic is as follows:

Table 15

Degree of wearing is used in the sandblast of abrasive particle lot number solution density crystalline size

(gm/cc) (micron) (mm)

A 3.94 1.16 3.91

B 3.93 0.65 3.84

C 3.89 0.54 3.83

D 3.92 0.42 4.14

E 3.90 0.39 4.16

F 3.88 0.26 3.92

G* 3.95 2.54 2.99

*: crystalline size is all recorded by the intercepting method.

Diameter with abrasive particle of circular cross section is 50 size corresponding to granularity.Be used to make identical ceramic bonding material and make the scope that each sample mill silk of the emery wheel that is of a size of 127mm * 12.7mm * 31.75mm has a slenderness ratio.Each emery wheel is repaired, made it to become the rectangle wheel face of wide 6.4mm, and can stand dry grinding and wet method grinding.

Dry grinding hardness is Rc60, and size approximately is the D3 steel plate of 100mm * 400mm.Speed of grinding wheel is 33.02smpm (6500SFPM).

No. 4340 hardened steel being of a size of 100mm * 400mm are adopted in the wet method grinding, and with the tap water ratio be the ID flexible nozzle of 1: 40 White and Bai Gelai (White and Bagtey) E55 refrigerant and 25mm.Speed of grinding wheel is 43smpm (8500SFPM).

Course of processing following parameters:

1. table speed is 15.24m/min

2. the downward amount of feed: dry grinding is 0.013,0.025 and 0.038 millimeter (0.5,1.0 He

1.5 mil)

Wet-milling is 0.013,0.025 millimeter (0.5,1.0) mil)

The feeding total amount is 2.54 millimeters (100 mils) downwards

3. measure abrasion of grinding wheel rate (WW), metallic substance grinding rate (mrr), smooth finish, power after the feeding downwards 2.54 millimeters (100 mil) and reactive force (except the amount of feed is 0.038 millimeter (1.5 mil), the dry grinding after 2.55 millimeters (100.5 mil).

4. use the single head diamond, with the downward amount of feed of 0.0254mm, the transverse feed speed trimming wheel of per minute 250mm.

The data that obtained are shown in following table 16 and the table 17.

It is the sol gel film of 54 commercial practices that the data of making comparisons relate to same material agglutinating granularity.

Table 16

The downward amount of feed average peak of model metallic substance wear rate abrasion of grinding wheel rate G-specific surface smooth finish

(mm) power (watt) (cm ³/ minute) (cm ³/ minute)

Relatively use: 0.013 940 4.048 0.0836 58.1 60

0.025 960 9.737 0.157 62.0 80

0.038 1120 14.48 0.292 49.8 100

G 0.013 400 1.696 2.707 0.6 240

0.025 500 3.177 5.124 0.6 320

0.038 640 4.769 7.951 0.6 300

A 0.013 720 3.874 0.7046 5.5 170

0.025 850 1.626 1.131 7.1 200

0.038 1000 11.77 1.462 8.1 280

B 0.013 800 4.311 0.493 9.7 120

0.025 1000 8.515 0.842 10.1 120

0.038 1120 12.97 0.844 15.4 260

C 0.013 640 4.301 0.390 11.0 110

0.025 960 9.065 0.511 17.7 150

0.038 1040 13.50 0.750 18.0 170

D 0.013 640 4.484 0.429 10.5 190

0.025 920 9.259 0.526 17.6 180

0.038 1120 14.00 0.519 26.9 200

E 0.013 480 4.282 0.405 10.6 190

0.025 690 9.095 0.546 16.7 180

0.038 920 13.58 0.772 17.6 200

F 0.013 680 4.777 0.129 37.1 170

0.025 880 9.567 0.256 37.3 200

0.038 1040 14.41 0.288 44.8 200

Table 17 dry grinding

The downward amount of feed average peak of model metallic substance grinding rate abrasion of grinding wheel rate G-specific surface smooth finish

(mm) power (watt) (cm ³/ minute) (cm ³/ minute)

Relatively use: 0.013 1,560 4.048 0.083 58.1 60

0.025 1760 9.737 0.157 62.0 80

G 0.013 960 1.214 3.287 0.4 230

0.025 960 2.320 6.493 0.4 200

A 0.013 880 2.330 1.955 1.2 120

0.025 1040 5.014 3.209 1.6 120

B 0.013 960 3.304 0.742 4.8 180

0.025 1120 6.942 1.245 5.6 110

C 0.013 1200 3.997 0.313 12.7 140

0.025 1360 7.414 1.083 6.8 110

D 0.013 1440 4.728 0.1639 29.0 120

0.025 1520 8.525 0.2769 30.7 200

E 0.013 1440 4.724 0.1508 31.2 100

0.025 1760 9.270 0.3245 28.6 130

F 0.013 1360 4.852 0.0705 69.0 120

0.025 1480 9.655 0.1720 59.1 120

May be clear that from above-mentioned data: when grain-size reduced, grinding performance significantly improved.In addition, in dry grinding, used power big more (increasing the downward amount of feed), wheel grinding good more.This is to make us unthinkable most.General experience is with the increase of putting forth effort, and G-because abrasive particle begins polishing, becomes invalid cutting edge than reducing.On the contrary, abrasive material of the present invention has only minimum extra abrasion of grinding wheel, is keeping mostly preferably.

Claims (15)

1. agglomerating sol-gel alumina base abrasive filaments, it comprises the agglomerating alpha alumina crystals that is of a size of 0.05～2 micron, described abrasive filaments has the cross section of uniformity basically, diameter is 0.1～100 micron or 0.25-1.5 millimeter, average slenderness ratio is greater than 1, and hardness is at least 16GPa.

2. abrasive filaments according to claim 1, its length is less than 1cm.

3. abrasive filaments according to claim 2, its slenderness ratio are 2: 1 to 8: 1, and diameter is 0.25mm to 1.5mm, and the size of wherein said alpha alumina crystals is not more than 1 micron.

4. abrasive filaments according to claim 2, its density is at least 95% of theoretical density, and including the oxide compound of 10% to 15% weight, described oxide compound is from zirconium white, titanium oxide, magnesium oxide, hafnium oxide, cerium dioxide, spinel, mullite, manganese oxide, these oxide compounds and just selects crystal and their mixture.

5. abrasive filaments according to claim 2, add in the wherein said alpha alumina crystals size less than 1 micron αYang Hualv as crystal seed.

6. agglomerating alumina-based abrasive silk according to claim 2, wherein said alumina-based abrasive silk is crooked in its lengthwise dimension direction.

7. agglomerating alumina-based abrasive silk according to claim 2, wherein said alumina-based abrasive silk curls in its lengthwise dimension direction.

8. agglomerating collosol and gel abrasive filaments according to claim 2, it is substantially devoid of glassiness composition, and breaking tenacity is at least 8000kg/cm ²

9. with the metal of the described mill silk of claim 1 reinforcement or the mixture of pottery.

10. the method for a manufacturing aluminium base filate thing of sintering oxidation that contains alpha alumina crystals, described alpha alumina crystals is of a size of 2 microns or littler, may further comprise the steps:

The superfine hydrated alumina particles is added in the entry and is stirred the stable dispersion of back formation, then with forming gel after this stable dispersion of acid treatment;

The dispersion of described gel is made filate;

Described silk is dry;

With described exsiccant silk roasting to the 1200 ℃ a certain temperature between 1350 ℃, used selection of time is for changing into the aluminum oxide in the described silk time of ceramic body, and the major portion of ceramic body is formed by being of a size of 2 microns or littler alpha alumina crystals.

11. method according to claim 10, wherein, the seed particles that comprises the superfine of significant quantity in the dispersion of described gel, described alpha alumina crystals is of a size of 1 micron or littler, is used for impelling described hydrated aluminum oxide to be converted into αYang Hualv rapidly when roasting.

12. method according to claim 10, wherein said alpha alumina crystals are of a size of 0.4 micron or littler.

13. method according to claim 10, wherein said seed particles is chosen from following oxide compound group: the first crystal of αYang Hualv, α ferric oxide, gamma-alumina, chromic oxide and αYang Hualv, gamma-alumina, chromic oxide, α ferric oxide and their mixture, the weight that described seed particles adds is 0.5% to 10%.

14. method according to claim 10, the shaping of the dispersion of wherein said gel forms by squeezing silk.

15. method according to claim 10, the dispersion of wherein said gel want shape get rid of the silk form.